It is now over 20 years since the seminal paper on energy law as a discipline was published. The aim of this article is to review what currently constitutes energy law after this 20-year hiatus. There are two main ambitions of this article, which we hope will have a similar impact on the field. The first is to develop for scholars and practitioners a view of what constitutes energy law—and to make this accessible to both law and non-law energy scholars. The second is to advance a set of core principles that guide energy law, in essence a treatise for energy law. We advocate for a paradigm shift in our current understanding of what constitutes energy law. We advance that it should revolve around this set of guiding principles; however, we acknowledge that to some degree it is perhaps not a paradigm shift due to the current absence of any core principles of energy law. Nevertheless we argue that in our advancing of a guiding set of principles we set out a new path for the study of energy law and thus we aim to change what constitutes energy law and challenge the assumptions of existing researchers as globally society moves towards a transition to low-carbon economies.